Below-grade remediation
A dry, healthy foundation starts below the surface.
ASM treats basement and crawl-space mold by locating the water or humidity source, containing affected areas, removing materials that cannot be safely restored and cleaning remaining surfaces. The final plan also addresses moisture control so the same conditions are less likely to return.
ASM treats basement and crawl-space mold by locating the water or humidity source, containing affected areas, removing materials that cannot be safely restored and cleaning remaining surfaces. The final plan also addresses moisture control so the same conditions are less likely to return.
What’s included
A complete scope,
not a surface fix.
Containment and HEPA filtration
Removal of unsalvageable porous materials
Concrete, wood and framing treatment
Drying and humidity recommendations
Final inspection and warranty certificate
How the work happens
Four clear stages.
One accountable team.
A contained basement area may take one to three working days. Broader demolition, structural drying or repairs can extend the schedule and are reviewed before work begins.
- 01
Trace the moisture
We check visible damage, humidity, foundation entry points and plumbing sources.
- 02
Build containment
The affected area is isolated before contaminated material is disturbed.
- 03
Remove and clean
Damaged porous materials are removed and restorable surfaces are professionally treated.
- 04
Keep it dry
We document practical drainage, ventilation and humidity-control recommendations.
Project scope
What shapes the work?
ASM confirms the responsible scope after a free inspection because materials, access, moisture source and containment matter more than a generic online estimate.
Book a free inspection ↗- 01Finished versus unfinished space
- 02Drywall or flooring removal
- 03Foundation or plumbing repairs
- 04Square footage and accessibility
- 05Drying and dehumidification needs
Proof after the work
Inspected. Documented.
Backed in writing.
After the job is completed and inspected, ASM provides a Mold Remediation Warranty Certificate for the serviced areas. It gives homeowners, buyers, sellers and real estate professionals a clear record of professional treatment.
See completed projectsLocal service guides
Basement & crawl space
across Ontario.
Choose a city for local building context, common moisture conditions, nearby coverage and links to every related ASM service.
Toronto and the GTABasement & crawl space in Toronto↗Peel RegionBasement & crawl space in Mississauga↗Peel RegionBasement & crawl space in Brampton↗York RegionBasement & crawl space in Vaughan↗York RegionBasement & crawl space in Markham↗Hamilton and HaltonBasement & crawl space in Hamilton↗Niagara RegionBasement & crawl space in Niagara Falls↗Durham RegionBasement & crawl space in Oshawa↗Durham RegionBasement & crawl space in Ajax↗Peterborough CountyBasement & crawl space in Peterborough↗Frontenac CountyBasement & crawl space in Kingston↗Simcoe CountyBasement & crawl space in Wasaga Beach↗Middlesex CountyBasement & crawl space in London↗Simcoe CountyBasement & crawl space in Barrie↗Waterloo RegionBasement & crawl space in Kitchener↗Waterloo RegionBasement & crawl space in Cambridge↗Waterloo RegionBasement & crawl space in Waterloo↗
Helpful answers
Questions about basement & crawl space
What humidity level helps prevent basement mold?+
Health Canada recommends maintaining indoor relative humidity between 30% and 50%. A dehumidifier, proper drainage and prompt leak repairs can help keep basement moisture under control.
Can mold behind drywall be cleaned without removal?+
If mold is inside porous drywall, the affected section often needs to be removed so hidden growth and damp materials can be addressed safely.
Will painting over basement mold solve it?+
No. Paint can hide staining but it does not correct the moisture source or remove contamination beneath the surface.
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Ready for a clear answer?
Start with a free inspection. We’ll explain what we found, what it takes to fix and what happens next.